Electrosurgery
and Latex Gloves
Electrosurgery and latex
gloves overview
Key terms
An inadvertent electrical burn or shock during
electrosurgery is frequently one of the occupational
hazards in the operating room. The person
experiencing the event usually attributes the incident
to a hole in his or her surgical glove. However,
there are several other causes of electrical shocks
or burns during electrosurgery. The purpose of this
information is twofold:
Current: The number of electrons moving past
a given point per second. Measured in amperes,
electrical current can be Alternating Current (AC),
meaning that positive and negative ions flow along
the current path in alternating directions, or Direct
Current (DC) with the flow of electrical current in one
direction only.
1. To provide a basic understanding of the principles
of electrosurgery as they relate to surgical gloves
and the phenomena of introspective burn or shock;
and
2. To create an awareness of all of the circumstances
that can cause such surgical hazards.
Capacitive coupling: The condition that
occurs when alternating (AC) electrical current is
transferred from one conductor (an electrode), across
intact insulation, into adjacent conductive materials
(tissue or skin) or another metal surgical instrument.
Capacitance is stored electrical charge.
Electrosurgery: The passage of Radio
Frequency (RF) or high-frequency electrical current
through tissue to create a desired clinical effect on the
tissue. RF current is measured in cycles per second.
Resistance (impedance): The lack of
conductivity or the opposition to the flow of electrical
current. Resistance is measured in ohms.
Dielectric breakdown: Breakdown of a
non-conductive material, i.e. rubber glove, which may
be caused by high voltage output from the electrical
generator.
Understanding the
relationship between
surgical gloves and
electrosurgery
What is electrosurgery?
Electrosurgery is the application of electrical RF
current to biological tissue. An electrosurgical
generator supplies the source of electric current,
which transfers energy (electrons) to tissue. The term
‘Bovie’, a manufacturer’s trademark named after one
of the early pioneers, Dr William T Bovie, is often
used synonymously with the term Electrosurgery.
The terms electrosurgery and electrocautery are also
often used synonymously; however, this is incorrect
and it is important that the two are not confused. In
electrosurgery, the electrical current is applied directly
to the tissue and the patient is part of the circuit.
Electrocautery is the indirect application of electrical
current by heating a conductive element, which
burns tissue. Another distinguishable difference is
that electrosurgical units are considered AC energy
sources and electrocautery units are DC sources. An
electrosurgery source is quickly identifiable in the
operating room by the ground electrode applied to the
patient.
How common is
electrosurgery?
The use of electrosurgery during an operative
procedure is almost as common as wearing gloves.
There are various energy sources and methods
employed with the use of electrosurgery. Radio
frequency current is typically used by the surgeon
to cut tissue or to obtain hemostasis (stop bleeding).
Electrosurgery is a safe and an efficient instrument
for both invasive and Minimally Invasive Surgical
(MIS) procedures.
How does and
electrosurgical unit
operate?
The circuitry of an electrosurgery unit is composed
of the generator, and active electrode (hand-held
instrument), the patient and the patient return
electrode which is sometimes referred to as the
passive or ground electrode (patient pad or plate).
Electrons or the the electrical charge travel from the
generator through the active electrode, through the
patient and returns to the generator via the patient
ground electrode, completing the electrical circuit.
See Diagram 1.
Diagram 1
At the point that the current passes through the
active electrode, the electrical energy is converted into
thermal energy that produces high-energy heat. The
heat causes disintegration of tissue cells, which may be
seen as desiccation (destruction), or hemostasis of the
tissue. Of course, the effect upon the tissue depends
on a multiplicity of factors such as the amperage of the
electrical current, the size of the active electrode tip and
the time the electrical generator is activated. A final,
but very important point to consider is the absolute law
of electricity, which is: ‘electrical current always follows
the path of least resistance’. During electrosurgery, if
the environment so dictates, the hand of the operating
surgeon or assistant may offer the optimal path.
What problems exist with
electrosurgery?
Advances in electrosurgical technology have
made it a safe and necessary practice in almost all
types of surgical intervention. However, there are
idiosyncrasies linked to the modality which warrant
astute awareness by all members of the healthcare
team involved when electrosurgery is used. Among
the potential concerns for the operative team are:
interference with video and anaesthesia monitoring
equipment, return electrode (pad) site burns and
alternate site burns to the patient which may occur if
the electrosurgical current is sufficiently concentrated
to a site other than the return electrode. Also, sparks
from an electrosurgery unit could provide an ignition
source for an intraoperative fire.
Another problem related to the use of electrosurgery
is electrical shock or burn to the operating surgeon
or assistant through the surgical glove.1 When this
occurs the clinician often attributes the hazard to a
pre-existing hole in the glove, i.e. break in insulation,
the clinician changes gloves and continues on. While
this may be the case, and changing gloves is likely to be
the solution, there are other variables to be considered.
It is possible that the hazard did not occur from a preexisting hole in the glove barrier but, in effect, a hole
could result from the electrical hazard.
The glove barrier may not have had a hole in it at all
before the episode occurred. It has been suggested
by researchers that the potential for a member of the
operative team to receive a shock or burn through the
surgical glove (natural rubber or synthetic) may occur
three different ways aside from a pre-existing hole.
Direct current conduction
This suggests that the impedance of the glove barrier
to the electrical current is low enough to let the
current pass through. The impedance or resistance
properties of a surgical glove may be reduced as result
of extended wear and exposure to blood and fluids
or from perspiration inside the glove. A ‘ballooning’
phenomenon can typically be seen at the tips of the
glove, which suggests that the glove has lost some of
its barrier protective property. Another term often used
to explain the barrier breakdown effect is ’hydration’,
simply defined as the absorption of water into the latex
film. A glove that has become hydrated measures a
lower electrical resistance than a non-hydrated glove.3
A surgical glove that hydrates slowly may offer added
protection against the problems associated with
electrosurgical shock. Routine regloving and doublegloving can prevent the problems as well.
See Diagram 2.
Diagram 2
Radio frequency capacitive coupling
During electrosurgery the operating surgeon’s
perspiring conductive skin and the metal hemostat
applied, for example, to a blood vessel, are considered
capacitors (two conductors) separated by an insulator,
the glove barrier. When alternating current is
applied to the hemostat from the active electrode, it
induces electrical charge on the other conductor. The
thinner the glove film, the more efficiently current
can be induced to surge from one conductor (the
hemostat) to the other conductor (the surgeon’s
hand). This does not imply that electrical shock is
imminent in every procedure; certainly, conditions
(as described in this bulletin) dictate. But what is
suggested in the literature is that all gloves, intact or
otherwise, are capable of transferring large amounts
of radio frequency current.1 Here again, selectively
choosing an optimal barrier (e.g. an ultra-thick glove)
may prove to be a more effective insulator for the
operating surgeon when employing electrosurgery.
See Diagram 3.
Diagram 3
High-voltage dielectric breakdown
This phenomenon results when the glove barrier
cannot withstand the effects of the high-energy force
from an electrosurgery generator. If the voltage is
sufficiently high, it can produce a hole in the glove
and a resultant burn. Again, there are contributing
variables such as the amount of time the current is
applied or the surgical technique used. For example,
it is a very common practice for the surgeon or first
assistant to clamp a bleeding vessel and ‘zap’ the
bleeder with the active electrode while holding onto
the hemostatic instrument. The voltage or force
from the generator is exerted onto the entire clamp.
The real potential for an electrical hazard is to the
person holding the clamp. If the clamp is being
held by just the tip of one finger, this allows only a
small area for the current to concentrate, increasing
the current density to the finger holding the clamp
– all conditions right – ‘zap’. Basically, it is the same
principle as touching a doorknob with your finger
and getting ‘zapped’ after walking across a carpeted
room and generating static electricity. A safe method
is to keep a firm hold on the hemostat while obtaining
hemostasis with the electrosurgery instrument.4 This
insures a larger area, decreasing the chance for the of
current at the site.
See Diagram 4
Diagram 4
Surgical gloves may be considered a nonconductor
due to the insulating properties of rubber and may be
considered by some to act as an insulation medium
when performing electrosurgery. However, glove
barriers are not manufactured for this purpose
and therefore should not be ‘relied upon to provide
fail safe’ insulation. Understanding how to ensure
optimal protection and performance is crucial in
healthcare now more than ever, particularly with the
overshadowing problems related to AIDS and other
bloodborne pathogenic diseases. The instruments and
equipment we depend on to deliver quality patient
care function the best when we do our best to operate
them correctly and effectively.
Recommended
reading
1. Tucker RD. The physics of electrosurgery.
Continuing education; Aug. 1985: 574-89.
7. Latex surgical gloves. Health devices sourcebook
1983; 12: 83-98.
2. Luciano AA, et al. Essential principals of electro
surgery in operative laparoscopy; J AM Assoc
Gynecol Lapar 1984; 1(3): 189-95.
8. Beck WC. Glove testing for holes. Guthrie Journal
1988; 57: 67-70.
3. Hausner K. Endoscopic electrode safety. Medical
electronics; April 1993: 94-6.
4. Odell RC. Biophysics of electrical energy,
In operative laparoscopy. The Master’s techniques.
New York Raven Press 1993: 35-44.
5. Tucker RD, et al. Capacitive couple stray current
doing laparoscopic and endoscopic electrosurgical
procedures. Biomed Instrum Tech 1992; 26: 303-11.
6. Pearce JA. Hazards in electrosurgery. London,
Chapman & Hall 1986: 179-223.
9. Brough SJ, et al. Surgical glove perforations.
Brit J Surg 1988; 75: 317.
10. Update: Controlling the risks of electrosurgery.
ECRI Health Devices Dec. 1989; 18(12): 430-2.
11. Vancallie TG. Electrosurgery: Principles and risks.
Center for gynecologic endoscopy, San Antonio,
TX 1994.
12. Charles NC, et al. Causes and Prevention of
Electrosurgical injuries in laparoscopy.
J Am Col Surg Aug. 1994; 179: 161-70.
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